1. Field of the Invention
The present invention relates to a recording apparatus having a recording head for forming an image on a recording medium and, more particularly, to a recording apparatus having an automatic paper feed device.
2. Related Background Art
The recording apparatus having the function of a printer, a copier, a facsimile machine, or the like, or the recording apparatus used as an output device for workstations and complex electronic devices including computers, word processors, etc., is constructed to record an image on a recording medium such as a paper sheet or a thin plastic sheet or the like, based on image information. These recording apparatuses can be classified by their recording methods; i.e., under the ink jet type, the wire dot type, the thermal type, the laser beam type, and so on.
In the recording apparatus of a serial type to perform a serial scan in a direction (main scanning direction) perpendicular to a carriage direction (sub-scanning direction) of the recording medium, an image is recorded (in a main scan) by a recording means mounted on a carriage moving along the recording medium, the recording medium is fed by a predetermined amount (pitch feed (conveying)) after completion of recording of one line, and the recording medium is stopped again thereafter to undergo recording of a next-line image (main scan). This operation is carried out repeatedly to perform recording on the entire area of the recording medium.
In the recording medium of a line type to perform recording by only sub-scanning in the carriage direction of the recording medium, the recording medium is set at a predetermined recording position, recording of one line is carried out in one step, the recording medium is then fed by a predetermined amount (pitch feed), and recording of a next line is further carried out in one step. This operation is carried out repeatedly to perform recording on the entire area of the recording medium.
Among the above-stated recording apparatus, the recording apparatus of the ink jet type (ink jet recording apparatus) is constructed to record the image by ejecting ink from the recording means (recording head) onto the recording medium and has such advantages that reduction in size of the recording means is easy, that a high-definition image can be recorded at high speed, that it can record an image on plain paper without necessity for an extra treatment, that the running cost is low, and that it makes little noise because of a non-impact method. In addition, it also has another advantage in that a color image can be recorded readily by use of ink liquids of multiple colors. Among others, the line-type apparatus using the recording means of the line type with a lot of ink ejection ports arrayed along the direction of the sheet width has the potential for further increase in the speed of recording.
Particularly, the recording means (recording head) of the ink jet type to eject the ink by making use of thermal energy can be produced readily in high-density liquid path layout (ejection port layout) by forming electrothermal transducers, electrodes, liquid path walls, top plates, etc. in films on a substrate through semiconductor fabrication processes such as etching, evaporation, sputter, and so on, and thus its structure can be reduced in size even further.
Use of advantages of the IC technology and microprocessor technology facilitates an increase in the length and formation in a surface (two-dimensional area) of the recording means and also facilitates full multi-color formation and high-density dot formation of the recording means.
In recent years, these recording devices are being equipped with an automatic paper feed device for storing a stack of recording media thereon and for feeding them one by one to a recording section while separating one from the others. Therefore, there is no need for setting each of recording media one by one for recording and this allows a large volume of recording to be carried out at once. For registration with the recording head in a printing area, a recording medium fed from the automatic paper feed device is positioned by a method of positioning the leading edge of the recording medium by a nip between a pair of carriage rollers located on the upstream side of the recording head or by a method of positioning the side of the recording medium by aligning it with a recording-medium reference surface on the upstream side of the recording head.
However, when the registration of the recording medium is made by the nip between the carriage roller pair, the carriage roller pair has to be kept stationary or be rotated backward in order to make the leading edge of the recording medium butt against the nip. This inevitably requires a longer time from the start of sheet feed to the start of recording and it is a bottleneck to increase in the recording speed in recent years, particularly, in the ink jet recording apparatus.
On the other hand, the registration at the side of the recording medium is free of such time loss for registration, but is apt to be affected by cutting accuracy of the recording medium and a guide member for guiding the side of the recording medium. This raised the issue that disturbance of the image became prominent due to registration deviation in the case of a high-quality mode in which recording was carried out in a longer time than in the case of a normal mode. Further, the case of small recording media in the size of postcards or the like, good registration was not made using only the guide member at the side and the above issue became more prominent in the case of the high-quality mode for photo-like images.
The present invention has been accomplished in order to solve the above problems and an object of the present invention is to provide a recording apparatus that permits remarkable increase of the throughput in recording of documents and that also permits good recording without disturbance of the image in the high-quality recording of photo-like images etc. other than the documents.
The present invention presents the recording apparatus characterized by having the following structure.
(1) A recording apparatus having a plurality of recording modes, said recording apparatus comprising an automatic sheet feed device for feeding recording media one by one and a pair of convey (carriage) rollers for conveying (carrying) a recording medium thus fed, to a recording section,
wherein a registration method of the recording medium to the recording section is selected according to said recording mode.
(2) The recording apparatus as set forth in (1), wherein when the recording mode is a high-quality mode, registration to align a leading edge of the recording medium with a nip between the carriage roller pair is selected, but said registration is not selected in a high-speed mode or in a normal mode.
(3) A recording apparatus having a plurality of recording modes, the recording apparatus comprising an automatic feed device for feeding recording media one by one and a pair of carriage rollers for carrying a recording medium thus fed, to a recording section, wherein a registration method of the recording medium to the recording section is selected according to the recording mode and a kind of said recording medium.
(4) The recording apparatus as set forth in (3), wherein when the recording medium is a special medium, registration to align a leading edge of the recording medium with a nip between the carriage roller pair is selected, but said registration is not selected when the recording medium is plain paper.
(5) The recording apparatus as set forth in (4), wherein said special medium is a recording medium other than the plain paper; e.g., coat paper or the like including a postcard.
(6) A recording apparatus capable of using a plurality of recording heads by replacing one with another, the recording apparatus comprising an automatic feed device for feeding recording media one by one and a pair of carriage rollers for carrying a recording medium thus fed, to a recording section, wherein a registration method of the recording medium to the recording section is selected according to the recording head.
(7) The recording apparatus as set forth in (6), wherein when the recording head is a color head for photo-like images, registration to align a leading edge of the recording medium with a nip between the carriage roller pair is selected, but said registration is not selected during use of a monochromatic head or a normal color head.